Sophisticated and expensive computers allow high-frequency traders to take advantage of minuscule differences in price among the many exchanges where securities are bought and sold. Some firms pay to place their computers on the site of a stock exchange to be sure their access to price data is as fast as possible, a practice known as colocation; others will use technology to obscure their trading intentions for a few crucial thousandths of a second. Lewis's book tells the story of Brad Katsuyama, a former trader at the Royal Bank of Canada in New York. Katsuyama opened a new stock exchange last year to give investors protection from HFT.

Lewis is not the first to cry foul on these strategies. Eric Scott Hunsader, the founder ofNanex, has made himself immensely unpopular in some circles for his outspoken and persistent criticism of HFT, which he first encountered during the "flash crash" of 2010. Bloomberg called him the "nemesis" and "scourge" of the HFT world...